/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License. You may obtain a copy of the License at the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>Unless required by applicable law or agreed to in writing, software distributed under the
 * License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apereo.portal.portlets.search;

import java.io.Serializable;
import java.util.Comparator;
import org.apereo.services.persondir.IPersonAttributes;

/** DisplayNameComparator allows the sorting of people by display name. */
public class DisplayNameComparator implements Comparator<IPersonAttributes>, Serializable {
    private static final long serialVersionUID = 1L;

    @Override
    public int compare(IPersonAttributes o1, IPersonAttributes o2) {
        Object name1 = o1.getAttributeValue("displayName");
        Object name2 = o2.getAttributeValue("displayName");
        if (name1 == null && name2 == null) {
            return 0;
        } else if (name1 == null) {
            return -1;
        } else if (name2 == null) {
            return 1;
        } else {
            return name1.toString().compareTo(name2.toString());
        }
    }
}
